The ever-expanding universe of social-media technologies — including video-sharing, mobile phones, and networking sites such as Facebook and Twitter that allow individuals to share and connect — is as ubiquitous as it is misunderstood. Apostles hail its power to oust dictators and bring us together; skeptics worry that it homogenizes our thinking and trivializes our relationships. Let’s separate fact from fiction.

Social media gives power to the people.

More than 5 billion people are connected via mobile phones, 2 billion are on the Internet, and Facebook boasts some 750 million users. With such wide reach, it’s easy to assume that communications technologies are great equalizers, increasing the political and economic power of the least well-off.

Certainly, there are examples of new technologies helping the less fortunate. Kenyan farmers and Indian fishermen have used phone applications to bypass corrupt middlemen and get real-time prices for their goods. Anecdotes abound of bloggers documenting human rights abuses, activists communicating via social media during the Arab Spring and indigenous people in Mexico using online newsgroups to promote their struggle for sovereignty. Even the current “Occupy Wall Street” effort was organized via social media.

But to best take advantage of a technology, people need dependable physical infrastructure and human capital — including electricity, education and media literacy. This is true even in the United States. For example, as a faculty member at UCLA, I have worked to develop a digital museum representing objects from the indigenous Zuni people of New Mexico in a way that respects their culture. Our research team found that designing the online system based on standard museum-style descriptions was alienating to the Zuni and that we needed to listen to their ways of describing the world, through storytelling and community rituals. If technologies are designed in isolation from the cultures they seek to connect, people’s real voices will not be heard.

Governments easily monitor and censor social media.

The Internet is much harder to police than capital-intensive media such as television, newspapers and radio. With these older media, intelligence authorities can more easily detect broadcast or printing locations. It’s not as simple to monitor a digital environment where anyone with a laptop, bandwidth and the requisite education can create his or her own media network by blogging, tweeting or streaming.

In 2006, my colleague Adam Fish and I were working in Kyrgyzstan, which maintained a Soviet-style approach toward policing media outlets and phone communications. We were surprised to learn that, partly because of the country’s need for foreign aid, authorities had agreed to relax Internet regulation in exchange for assistance. We also learned how hard it was to monitor Internet users who were widely dispersed, in some cases using proxy servers and IP-address-scrambling technologies to evade surveillance.

As our research proceeded, we found a small blogosphere emerging in Kyrgyzstan, linking activists and opposition politicians with one another and with sympathizers throughout Central Asia, Russia and the West. The activists understood that the Internet would hardly be sufficient to oppose the regime, but they also found that social media helped them communicate, building ties that fueled at least part of the revolutionary leadership that toppled President Kurmanbek Bakiyev in April 2010.

Facebook and Twitter enabled the

Arab Spring.

Even if social-media networks provide activists with new tools to combat repression, they rarely direct social movements — particularly because they don’t necessarily drive people onto the streets. While I was in Egypt this summer, citizens explained why they flocked to protests early this year. Their stories focused on hardship and grievances; admiration of the Tunisian revolution; and the power of “street networks,” or the techniques used by mosques, unions and community organizers to rally people in the working class, almost none of whom use social media. (Less than 5 percent of Egypt’s population uses Facebook, and less than 1 percent uses Twitter.) Some Egyptian bloggers explained to me that they came to Tahrir Square only after the Mubarak regime hit the “kill switch” on the Internet; they also described unsuccessful protests they tried to organize on Facebook. In addition, activists explained that governments can use social media to monitor dissidents, infiltrate movements and spread propaganda.

That said, social media has indirect effects on mobilizing people, including the ability to organize the networks of key activists and shape news coverage. Egyptian TV journalists said to me that they often source stories from Twitter and circulate videos originally shot on mobile phone and disseminated via video-sharing sites.

Only young people use social media.

Social media appeals to people of all ages in the Western world, where the most reliable data is available. In the United States, 60 percent of Facebook users are at least 35, and the average age of a Twitter user is now 39 — meaning that many people who were not exposed to the Internet until their 20s are now a big part of its user base. Two-thirds of all American adults use social-networking sites, according to the Pew Research Center, and a 2010 study found that 42 percent of Americans over age 50 are social-media users.

The growth of mobile phone and video-sharing technology mirrors this trend. A recent Pew study found that smartphone users in the United States text and share media across all ages, though youth do so more often.

Social media creates a global village.

We’ve long heard that the Internet was supposed to unite people of different cultural and political persuasions. Yet, despite the explosion of online voices, social-media users rarely access opinions that differ from their own, and many social-media sites — with their bifurcated like/dislike, join/don’t join ethos — only perpetuate the sound-bite culture of older media.

Not only are our Facebook friends similar to us (we usually connect through mutual friends and shared interests), but researcher Ethan Zuckerman has shown that the sites we visit reaffirm our political and cultural preconceptions. This homogenization reaches the very machinery of social media — its algorithms — which tailor search results or Facebook feeds according to what the systems “think” users will find most interesting.

Bridging disparate cultural and political backgrounds remains a challenge for social media. To learn from differing viewpoints, the technologies and cultures of social media must evolve so that they bring people together rather than keeping us in digital silos.

Ramesh Srinivasan is an assistant professor of information studies and design/media arts at the University of California at Los Angeles. Distributed by Washington Post-Bloomberg.